Hi Everyone.
I have a *friend* who's installing a VPC w/ 550 chip in his 99 GSX. We put it in the car, but the car is running rich no matter how much we try to lean it out. Idle was really erratic at first jumping back and forth from 300 - 500 rpm's, but we finally got that under control and running at about 750 rpm's. It's not the head unit because we put it in someone else's car and it works fine. If you need any more info, I'll happily post it.

FPBig 28
GReddy FMIC
RC 550's
Walbro 255
VPC
GReddy bov

Thanks.

dsmtrick

Otis

10-11-2002, 09:06 AM

Try an Adj. FPR. The base fuel pressure may be too much. Other than that I don't know shit about the VPC so I'm usless.

dsmtrick

10-11-2002, 09:15 AM

Not useless at all! That's funny you say that because I was just asking someone if that's what it could be.....lets see what everyone else thinks.

Thanks!

dsmtrick

10-16-2002, 03:20 PM

Anyone? :(

jw

10-16-2002, 03:33 PM

VPC is very sensitive to intake pressure so you will want to be sure the base fuel pressure is right. Also, have you tried playing the the VPC settings? Try lean the idle knob as much as possible and the gain knob will also affect the idle. If you lean out on the idle knob to say -8 and then you rich the gain knob to +2. The idle setting is actually -8+2 in this case. I found that out because I was trying to lean out on idle but rich things up on the gain and my idle became rich again. VPC usually idle rich from what I have heard so far. Also, the response has to be set all the way on the rich side for the tip-in to work properly.